Shanghai Chongming Island And The New Bay City Polycyclic Aromatic Hydrocarbons And Polychlorinated Biphenyls Distribution Characteristics

Concentrations of Polycyclic Aromatic Hydrocarbons(PAHs) and polychlorinated biphenyl(PCBs) in soil and core sediment samples taken from Chongming island and Xin Jiangwan district of Shanghai city were separately measured by gas chromatography and gas chromatography-mass spectrometer.The distributions were discussed based on the concentrations.Sixteen kinds of prior controlled PAHs by US EPA were identified in the core sediment of Dongtan Wetland of Chongming Island.The total concentrations ranged from 51.3 to 204.7ng/g dw.It was unlikely to influences the ecology for the concentrations were under the effects range low(ERL) values compared to the risk assessment values.Combustion of fuels may be the dominant source in the study area, depending on the ratios of Phe/Ant,Flth/Pyr,low circle PAHs/high circle PAHs.All of seven kinds of polychlorinated biphenyl(PCBs) were also identified.The concentrations of PCBs inspected and measured were 0.14～0.40ng/g dw.The residues of PAHs and PCBs changed dramatically with the depth.Combined with ²¹⁰pb dating,the vertical distributions of PAHs with times were studied.The total PAHs in the soil of east of Chongming ranged from 64.6 to 717.2 ng/g dw, showing a low pollution level compared with the limited values of PAHs in soil in foreign countries.Combustion of fuels was figured out to be the main source of PAHs.The total concentrations of PAHs in Xin Jiangwan district ranged from 1158.1 to 8050.8ng/g dw,which showed that it has been contaminated by PAHs to some extent.It also should be contributed to the combustion of fuels.Not all the seven kinds of PCBs were detected in the samples of Xin Jiangwan district.The concentrations of PCBs in this area ranged from1.83 to 8.46ng/g dw,lower than the residues of some typical polluted region.